Fourth snakehead is caught in Potomac in Va.

Alien species found in Anne Arundel pond

A fisherman has caught another northern snakehead fish in the Potomac River in Virginia, state officials announced yesterday, marking the fourth time this spring that the voracious Asian invader has turned up in the river.

A commercial waterman caught the 14 1/2 -inch, 1-pound fish near Fort Belvoir, in the same eight-mile stretch where the other snakeheads were caught. A Maryland Department of Natural Resources biologist confirmed that it was a female northern snakehead and was about 2 years old. A multiagency effort is under way to determine if the fish has established itself here.

The snakehead, a voracious predator native to China that can use its fins to move on land, can survive year-round in Maryland. Anglers who catch the fish should kill it with a blow to the head, put it on ice and notify authorities.